PBI based coatings are known. In U.S. Pat. No. 5,549,946, a PBI varnish is used to coat a metallic roll in a copying machine. In U.S. Pat. No. 5,674,614, U.S. Pat. No. 5,725,953, and U.S. Pat. No. 5,998,027, PBI varnishes are used to insulate electrical wire.
Mixtures of PBI and PVB have been prophetically mentioned for use is some applications. In U.S. Pat. No. 7,005,674, a PBI/PVB mixture is prophetically mentioned for use as an insulating layer in an organic thin film transistor (OTFT). In U.S. Pat. No. 7,166,412, a PBI/PVB mixture is prophetically mentioned for use as a non-conducting polymer carrier of photosensitive metal nanoparticles. In U.S. Pat. No. 7,960,458, a PBI/PVB mixture is prophetically mentioned as a resin composition carrier for a flame retardant.
There is a need for improved coatings, specifically coatings based on PBI and its unique chemical, physical, and electrical properties.